The Swamp level (and related levels) is by far the ugliest level of the game. It looks more like a dummy/test/WIP level than anything else. And yes, this is in version 1.0.

The tiles have sharp boundaries and the walkable dirt tiles look very wrong as well. There is no smooth transition at all, like with most other tiles in the game that look much better.

The player can clearly see the black void (rather than ocean) when you reach the level bounds. This affects the nearby levels to the East as well.

Was the Swamp accidentally left in release? Because this really looks like a very WIP level.

To fix the Swamp, I guess more and better graphical tiles are needed. Also a few decorations (trees, etc.) would be nice so the Swamp actually looks like a real swamp rather than just flat tiles.

As a temporary solution, I suggest to completely lock off access to the Swamp level (maybe with water tiles) while it is still ugly. Because right now, the only reason for the Swamp is access to the puzzle guy. It's a nice addition but IMHO it should only be accessible in a 1.x release when it is actually fully-polished.

For the same reason, access to the mines south of Town has already already been rightfully locked off in 1.0 since it is a WIP section.